[001/119] nilfs2: fix kernel oops in error case of nilfs_ioctl_move_blocks

Greg KH
2009-12-07T00:12:26Z

[-- Attachment #1: nilfs2-fix-kernel-oops-in-error-case-of-nilfs_ioctl_move_blocks.patch --]
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2.6.31-stable review patch. If anyone has any objections, please let us know.

------------------
From: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>

commit 5399dd1fc8f5e812db931225ef5f67d89f3b1a56 upstream.

This fixes a kernel oops reported by Markus Trippelsdorf in the email
titled "[NILFS users] kernel Oops while running nilfs_cleanerd".

The oops was caused by a bug of error path in
nilfs_ioctl_move_blocks() function, which was inlined in
nilfs_ioctl_clean_segments().

nilfs_ioctl_move_blocks checks duplication of blocks which will be
moved in garbage collection. But, the check should have be done
within nilfs_ioctl_move_inode_block() to prevent list corruption among
buffers storing the target blocks.

To fix the kernel oops, this moves forward the duplication check
before the list insertion.

I also tested this for stable trees [2.6.30, 2.6.31].

Reported-by: Markus Trippelsdorf <markus@trippelsdorf.de>
Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

---
fs/nilfs2/ioctl.c | 30 +++++++++++++-----------------
1 file changed, 13 insertions(+), 17 deletions(-)

--- a/fs/nilfs2/ioctl.c
+++ b/fs/nilfs2/ioctl.c
@@ -297,7 +297,18 @@ static int nilfs_ioctl_move_inode_block(
(unsigned long long)vdesc->vd_vblocknr);
return ret;
}
- bh->b_private = vdesc;
+ if (unlikely(!list_empty(&bh->b_assoc_buffers))) {
+ printk(KERN_CRIT "%s: conflicting %s buffer: ino=%llu, "
+ "cno=%llu, offset=%llu, blocknr=%llu, vblocknr=%llu\n",
+ __func__, vdesc->vd_flags ? "node" : "data",
+ (unsigned long long)vdesc->vd_ino,
+ (unsigned long long)vdesc->vd_cno,
+ (unsigned long long)vdesc->vd_offset,
+ (unsigned long long)vdesc->vd_blocknr,
+ (unsigned long long)vdesc->vd_vblocknr);
+ brelse(bh);
+ return -EEXIST;
+ }
list_add_tail(&bh->b_assoc_buffers, buffers);
return 0;
}
@@ -335,24 +346,10 @@ static int nilfs_ioctl_move_blocks(struc
list_for_each_entry_safe(bh, n, &buffers, b_assoc_buffers) {
ret = nilfs_gccache_wait_and_mark_dirty(bh);
if (unlikely(ret < 0)) {
- if (ret == -EEXIST) {
- vdesc = bh->b_private;
- printk(KERN_CRIT
- "%s: conflicting %s buffer: "
- "ino=%llu, cno=%llu, offset=%llu, "
- "blocknr=%llu, vblocknr=%llu\n",
- __func__,
- vdesc->vd_flags ? "node" : "data",
- (unsigned long long)vdesc->vd_ino,
- (unsigned long long)vdesc->vd_cno,
- (unsigned long long)vdesc->vd_offset,
- (unsigned long long)vdesc->vd_blocknr,
- (unsigned long long)vdesc->vd_vblocknr);
- }
+ WARN_ON(ret == -EEXIST);
goto failed;
}
list_del_init(&bh->b_assoc_buffers);
- bh->b_private = NULL;
brelse(bh);
}
return nmembs;
@@ -360,7 +357,6 @@ static int nilfs_ioctl_move_blocks(struc
failed:
list_for_each_entry_safe(bh, n, &buffers, b_assoc_buffers) {
list_del_init(&bh->b_assoc_buffers);
- bh->b_private = NULL;
brelse(bh);
}
return ret;